This section provides background information related to the disclosure that is not necessarily prior art.
In the following description, the expression “closure panels” will be used to generally indicate any component or element moveable between an open position and a closed position, respectively opening and closing an access to an inner compartment of a motor vehicle. As such, the term closure member shall include, without limitation, rear hatches, tailgates, liftgates, bonnet lids, deck lids and trunk lids in addition to the side doors of a motor vehicle to which the following description makes specific reference and purely by way of example.
In view of increased consumer demand for motor vehicles equipped with advanced comfort and convenience features, many modern motor vehicles are now provided with passive entry systems to permit locking and release of closure panels (i.e., doors, tailgates, liftgates and decklids) without use of a traditional key-type entry system. In this regard, some popular features now available with vehicle latch systems include power locking/unlocking, power release and power cinching. These “powered” features are provided by a latch assembly mounted to the closure panel and which includes a ratchet and pawl type of latching mechanism controlled via at least one electric actuator. Typically, the closure panel is held in a closed position by virtue of the ratchet being positioned in a striker capture position to releaseably retain a striker that is mounted to a structural portion of the vehicle. The ratchet is held in its striker capture position by the pawl engaging the ratchet in a ratchet holding position. To release the closure panel from its closed position, the electric actuator is actuated to move the pawl from its ratchet holding position into a ratchet release position, whereby a biasing arrangement forcibly pivots the ratchet from its striker capture position into a striker release position so as to release the striker. As an alternative, it is also known to employ a double pawl type of latching mechanism to reduce the release effort required for the electric actuator to release the latching mechanism.
As is known, such electrically-operated or “power” latch assemblies must also be capable of permitting the vehicle door to be opened in the event of emergency situations, such as in the case of an accident or crash involving the motor vehicle. In particular, during a vehicle crash or other emergency situation, the vehicle doors must be kept closed independently of handle activations or other used external interventions, such power latch assemblies commonly referred to as operating in a “double locking” status. However, after the crash, the vehicle doors should be capable of being opened with the power latch assembly returning to its “unlocking” status. In some vehicles, a crash management system is employed which is configured to detect a crash situation (via crash sensors) and issue suitable control signals to the electric actuators (typically electric motors) of the power latch assembly in order to automatically shift into the double locking status during the crash situation and subsequently return to the unlocking status a certain amount of time after the crash situation. However, during such an emergency situation, failure of the vehicle's main power supply, or interruptions or breaking of the electrical connections between the main power supply and/or the crash management controller and the power latch assembly may occur. Accordingly, such power latch assemblies with a power release function, typically require one or more emergency or “backup” mechanical release mechanisms to open the vehicle closure panel in the event power is not available. One way to provide this function is to connect a key cylinder lever, by rod or cable, to a release lever at the latch mechanism which is connected (directly or indirectly) to the pawl. This solution may also protect against the effects of inertia occurring during a crash event, since the key cylinder remains in a rest position until a key is inserted and rotated.
One drawback associated with conventional mechanical release systems is that relative movement between the key cylinder and the power latch assembly may occur during the crash event. To avoid unintentional activation of the release mechanism, efforts have been directed to enhance the connection and functional interaction of the components interconnecting the key cylinder and the release lever acting on the pawl. Specifically, a need continues to exist to develop an alternative to “single” motion release lever activation configurations.